There are two major objectives of this research, both of which relate to the general objective of learning more about the effects of early nutritional deprivation in primates. The first objective is to determine and to define the initial status, the growth, the development and the adaptive capacity of infant monkeys born of mothers fed different levels of protein during pregnancy. The second major objective is to produce during the period of the grant a group of infant rhesus monkeys born of mothers fed 1, 2, or 4 grams of protein per kilogram of body weight per day during pregnancy and who are maintained on diets inadequate in protein during the first 120 days of postnatal life. These animals will be examined and tested on an extensive battery of biochemical, radiological, urological, physiological and behavioral measures.